Langevin simulations of rod-shaped object alignment by surface flow

► We derive the probability density function describing the orientations of objects and show that it satisfies a Fokker-Planck equation. ► We evaluate the orientation probability density function for a range of the Peclet number α covering several orders of magnitude. ► We provide the experimental detection of orientation control with surface flow from the measurement of dichroism and birefringence of the suspension.